Download or copy from your computer the needed libraries (msvcp71.dll, msvcr71.dll) to your K-Meleon folder in your USB memory device. (This files are included in K-Meleon with installer versions, you can extract files from installers exe with 7zip)

Now start K-Meleon from USB memory only and config; Cache, History, Cookies.

In cache preferences, uncheck "Cache files on disk" option, and set "Cache files in memory" to 20 or 30 MB, optional: you can uncheck also "cache website icons on disk" option.
In history, set "Keep a list of all pages visited..." option to 0 (zero) days.
Set others privacy options as cookies and remember login data as you like it.

You can deleted setdefault.exe and loader.exe in your USB memory device K-Meleon folder because I don't think they would be needed on portable version.

How to avoid xpcom_core.dll create an empty directory in %appdata% folder.

You can download from here the modified file resulted: xpcom_core.dllNote: This xpcom_core.dll file could not be upgraded to the latest version of K-Meleon.